Sponge brakes?

[88lance]

Hello everyone, got an '02 Z71 Tahoe. The brakes seem to just be getting more and more spongy.

Today I replaced the front pads, and now it's worse than ever. It won't even try to slide tires on a gravel road.

When the brake pedal is pushed, it makes the "whoosh" sound and goes almost to the floor.

I checked fluid, and it is full. I don't see any sign of leaks. I have had the Tahoe for about 6 months and 13k miles and have never had anything done to the brakes, so whatever it is has gotten worse on its own.

I read this could be the master cylinder, but then also something about the booster. I removed the line from the booster and plugged it, and pushed the brake, and it was solid and would not go down. Maybe this means the booster is good, and points more to the master cylinder?

Before I tore into anything, I figured I would ask here just in case it was something that was an obvious fix for those who had experienced it before.

 

[88lance]

Nobody?

 

[OR VietVet]

I would first ask, did you just buy this or have owned for a while and the brakes were good when you got it but now you have the problem? When you did the front brake pads, did you clean and use high temp caliper lube for the slides? Should have. Have you checked the rear? If so, did you look to see if the pads are snug up to the rotors or is there a gap? i am talking on all 4 pads. Those caliper slides should be cleaned and lubed too and while you are at it, go ahead and replace pads and make them all new. Make sure to inspect for any signs of leakage at the caliper pistons, like you should have done on the front calipers. Clean and adjust as needed on the park brake shoes and hardware while in there.

Now, on to what I would inspect the very first thing. Unbolt the master cylinder from the front of the booster. leave the lines attached and pull away from booster and inspect for any signs of fluid leakage at back of master cylinder. Look at master cylinder and in the pocket of the booster. Inspect the push rod that is in booster and would insert in back of the master cylinder. Pics of all this is always good.

 

[Marky Dissod]

Hello everyone, got an '02 Z71 Tahoe. The brakes seem to just be getting more and more spongy.

Today I replaced the front pads, and now it's worse than ever. It won't even try to slide tires on a gravel road.

When the brake pedal is pushed, it makes the "whoosh" sound and goes almost to the floor.

I checked fluid, and it is full. I don't see any sign of leaks.
I have had the Tahoe for about 6 months and 13k miles and have never had anything done to the brakes, so whatever it is has gotten worse on its own.

I read this could be the master cylinder, but then also something about the booster.
I removed the line from the booster and plugged it, and pushed the brake, and it was solid and would not go down.
Maybe this means the booster is good, and points more to the master cylinder?

Before I tore into anything, I figured I would ask here just in case it was something that was an obvious fix for those who had experienced it before.

About 2 yr ago, back when I bought this Tahoe, I had pretty much the same problem.
Impersonating M. Bison's stomp was not guaranteed to lock the front brakes.
Pad upgrade was no improvement. I was driving like a normal person, out of FEAR.

If you have 17" or larger wheels, just order and install the following:
front caliper brackets
front calipers
front rotors
pads of your choice
for a 2010 Suburban.
All the questions I had were a waste of time. It all just fits as if it was meant.
No diagnosis needed. It's no Caprice 9C1, but I can drive like a jacques-arse again.

If you do not have 17" wheels, GET 17" WHEELS. It'll be worth it. TRUST ME.

FYI, I chose carbon-ceramic pads. More aggressive pads brake better, at the cost of rotor life.

 

[88lance]

Thanks for the replies. Everything looks good, and everything is properly greased, but I haven't disconnected the master cylinder from the booster yet, so I'll go ahead and check that tomorrow.

I do have the 17's, I didn't know about this brake upgrade with the 2010, that's great. I may add this to my list of improvements for it!

 

[rockola1971]

Check your rubber hoses for collapsing. If you are 100% sure you are not losing any fluid then your master cylinder is likely done for.

 

[Marky Dissod]

I do have 17s, didn't know about this brake upgrade with the 2010, that's great. I may add this to my list of improvements for it!

Compare the prices of an '02 OE brake kit vs a '10 OE brake kit.
Replacing the '02 front pads was a WASTE of time & money; I was still driving afraid.
The '02 OE front brake kit is NOT worth replacing - only upgrading.
I should've immediately done the '10 maintenance upgrade.

 

[buckwild27]

Thanks for the replies. Everything looks good, and everything is properly greased, but I haven't disconnected the master cylinder from the booster yet, so I'll go ahead and check that tomorrow.

I do have the 17's, I didn't know about this brake upgrade with the 2010, that's great. I may add this to my list of improvements for it!

If you wanted to upgrade wheel size you could upgrade to the 2019+ front brakes. If you wanted to of course.

 

[88lance]

Update, after replacing all the pads, the brakes feel almost normal again, although a little spongy compared to other vehicles still.
Even though this seems to have done a lot of good, I'll probably still look into one of these newer model upgrades since y'all mentioned it.

 

[buckwild27]

Update, after replacing all the pads, the brakes feel almost normal again, although a little spongy compared to other vehicles still.
Even though this seems to have done a lot of good, I'll probably still look into one of these newer model upgrades since y'all mentioned it.

A complete brake fluid flush might do some good if you haven't changed the brake fluid. It's one of those things that gets overlooked, but should be changed out every 1-2 years. Sooner if you have heavy brake usage.
You could also upgrade to DOT 4 brake fluid. It has a higher boiling point and has the capability of absorbing water.